JP2017205860A - Machine tool rotary table device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device configured so as to be able to realize a completely sealed state without any reduction in sealing performance caused by abrasion or the like in a machine tool rotary table device in which a rotary shaft is rotatably supported by a bearing in a frame storage hole and rotary driven at a high speed.SOLUTION: The rotary table device is provided with an air-sealing mechanism for preventing the entry of a foreign object into a frame by supplying compressed air to an airflow path through a gap in a frame defined by the inner peripheral surface of a frame storage hole and the outer peripheral surface of a rotary shaft closer to a table side than a bearing so as to eject the compressed air from the inside of the frame, and characterized in that the airflow path has a storage part on the upstream side of an ejection part located on the most downstream side of the airflow path, and the storage part has a path width larger than the flow path width of a part on the downstream side of the storage part in the airflow path.SELECTED DRAWING: Figure 1

Description

  The present invention has a rotating shaft having a disk-like table to which a workpiece is attached fixed at one end, a receiving hole for receiving the rotating shaft, and rotatably supporting the rotating shaft by a bearing in the receiving hole. A rotating frame, a driving device that rotationally drives the rotating shaft, and a clamp device that holds the rotating shaft at the indexed angular position during indexing. The driving device rotates the rotating shaft around the rotating shaft. The present invention relates to a rotary table device for a machine tool that is rotationally driven at a speed of 10 m / s or more.

  Generally, a rotary table device for a machine tool has a rotary shaft in which a disk-like table to which a workpiece is attached is fixed at one end, a receiving hole for receiving the rotating shaft, and a bearing in the receiving hole. And a frame that rotatably supports the rotation shaft, and the rotation shaft is rotationally driven by a drive device that uses a drive motor as a drive source. In addition, such a rotary table device performs contouring processing in which a workpiece is processed while continuously rotating the table in a machine tool, or processing a workpiece by fixing a rotation shaft at an indexed angular position. It is used to perform positioning processing. Since the rotary table device is also used for such positioning processing, the rotary table device also includes a clamp device for holding the rotary shaft at the angular position determined by the drive device (fixing the angular position). Yes.

  Further, in such a rotary table device, in order to prevent coolant liquid used at the time of workpiece processing, chips generated at the time of processing from entering the inside of the frame, the end portion on the table side of the accommodation hole in the frame In addition, a configuration including a seal member and a seal mechanism (hereinafter collectively referred to as a “seal device”) in a form of being interposed between the rotating shaft and the frame is generally used. The rotary table device disclosed in Patent Document 1 also includes such a sealing device. Incidentally, the sealing device disclosed in Patent Document 1 is a contact type oil seal. In addition to the oil seal disclosed in Patent Document 1, a sealing device used for the rotary table device includes a V-ring as a contact-type seal member, a labyrinth seal as a non-contact-type seal mechanism, and the like. Exists.

JP 2009-184021 A

  By the way, in the rotary table device, when a contact type seal member such as the oil seal or V ring as described above or a non-contact type labyrinth seal is adopted as the seal device, the following problems may occur. is there.

  First, in the case of a contact-type seal member, the seal member is provided in such a manner that it is fixed to one of the frame and the rotating shaft and is in sliding contact with the other. Therefore, since the seal member is in a state of sliding with the rotation shaft or the frame as the rotation shaft is driven to rotate, wear is inevitable. And if the wear progresses, the sealing performance by the sealing member in the rotary table device will deteriorate. In addition, when the rotary table device is used under a usage condition in which the rotating shaft is rotationally driven at a high speed such as a peripheral speed of 10 m / s or more as the premise of the present invention, the sealing performance due to wear of the sealing member is reduced. Decrease occurs early.

  In the rotary table device, when the sealing performance is deteriorated as described above, the above-described coolant liquid, chips and the like are likely to enter the frame. For this reason, it is necessary to perform an operation for replacing the seal member in accordance with wear. However, in the rotary table device used under the use conditions as described above, it is necessary to frequently perform the replacement operation.

  In particular, in the case of a seal member such as a V-ring, the seal member may be provided in a form that is fixed to the rotating shaft side for design (or device configuration) reasons. In that case, when the rotating shaft is rotationally driven at a high speed as described above, the contact portion of the seal member with the frame rises, and a gap is created between the seal member and the frame. As a result, the coolant liquid, chips and the like are liable to enter from the gap, so that the sealing performance by the sealing member is significantly reduced.

  Also, in the case of a labyrinth seal, since the relative rotating part does not contact (non-contact type) mechanism, unlike the contact type sealing member as described above, the sealing performance is deteriorated due to wear. There is no. However, since the labyrinth seal has a non-contact structure, it is inferior in terms of sealing performance as compared to a contact-type seal member. In some cases, the coolant liquid penetrates into the gap inside the capillarity. As a result, there is a possibility that the coolant liquid may enter the frame, and there is a problem that a complete seal state cannot be realized.

  Accordingly, in view of the problems of such a conventional apparatus, the present invention is a rotary table apparatus configured as described above, and is used under the usage conditions in which the rotary shaft is rotationally driven at a high speed as described above. It is an object of the present invention to provide a sealing device capable of realizing a complete sealing state while having a configuration in which a deterioration in sealing performance due to wear or the like does not occur.

  The present invention has a rotating shaft fixed to one end of a disk-like table to which a workpiece is attached, a receiving hole for receiving the rotating shaft, and rotatably supports the rotating shaft by a bearing in the receiving hole. A rotating frame, a driving device that rotationally drives the rotating shaft, and a clamp device that holds the rotating shaft at the indexed angular position during indexing. The driving device rotates the rotating shaft around the rotating shaft. A rotating table device for a machine tool that is rotationally driven at a speed of 10 m / s or more is assumed.

  In order to achieve the above object, the present invention is characterized in that a rotary table device as a premise thereof is configured as follows.

  The rotary table device communicates with a gap inside the frame defined by an inner peripheral surface of the housing hole and an outer peripheral surface of the rotary shaft in the frame, and is located on the table side with respect to the bearing. In this way, the air seal mechanism includes a supply flow path formed in the frame, and the compressed air is supplied by the supply flow path so that the gap functions as an air flow path and the compressed air is supplied to the air flow path. Is provided with an air seal mechanism that ejects compressed air from the inside of the frame to prevent foreign matter from entering the inside of the frame. And the said air flow path has a storage part upstream from the ejection part which is the most downstream part in the said air flow path, The said storage part is rather than the said storage part in the said air flow path The channel width is larger than the channel width of the downstream portion.

  The “channel width” in the above refers to the frame defining the air channel in a direction orthogonal to the direction of flow of the compressed air supplied into the air channel toward the ejection portion. And the frame or the rotation axis. However, the “direction of the flow toward the ejection part” here refers to the air flow path of the compressed air flow generated in the air flow path when the compressed air is supplied to the air flow path. The direction of the flow excluding the flow in the circumferential direction. More specifically, the air flow path exists circumferentially around the rotation axis, and along with the supply of compressed air to the air flow path, the air flow path on the supply flow path side in the air flow path. Compressed air flows from a position on the substantially same circumference (the most upstream side) toward the ejection part, and the compressed air is ejected from the ejection part. In addition, compressed air flows in the circumferential direction of the air flow path. However, the “direction of flow toward the ejection portion” referred to here does not include the direction of flow toward the circumferential direction as described in “toward the ejection portion”, and the ejection direction from the upstream side. It refers only to the direction of flow toward the section.

  In the present invention, the rotary table device communicates with the supply passage formed in the frame with respect to the gap existing in the frame, and the air supply device provided outside through the supply passage. By supplying compressed air to the gap, the gap functions as an air flow path for the compressed air. In the rotary table device, the compressed air is supplied to the air flow path because the air flow path communicates with the outside on the table side at the ejection portion which is the most downstream portion. Compressed air is ejected from the ejection part in the air flow path to the outside on the table side. Thereby, according to the turntable device of the present invention, at least during the processing of the workpiece, the compressed air is supplied to the air flow path so that the compressed air is ejected from the ejection part, so that it can be used during the machining. Intrusion of foreign matter such as coolant liquid and chips generated during the processing into the frame is prevented by the action of compressed air ejected from the ejection portion.

  The foreign matter enters from the opening on the table side in the gap in the frame, and the sealing device targeted by the present invention has a sealing effect that prevents the foreign matter from entering the vicinity of the opening in the gap. The presence of the sealing element that causes the occurrence of the foreign matter is prevented. In addition, in the rotary table device according to the present invention, the sealing element is compressed air, which is different from a contact-type seal member that realizes a sealed state by contact of the member. The sealing device is a non-contact type sealing device. Accordingly, the sealing performance is not deteriorated due to wear unlike the contact type seal member described above. Moreover, the compressed air as the sealing element exists over the entire vicinity of the opening of the gap, and unlike the labyrinth seal which is the same non-contact type sealing device, the coolant liquid is present within the existing range. Since there is no space (gap) that can enter, the sealing device can realize a complete sealing state.

  By the way, when realizing a sealed state with compressed air as described above, a state in which compressed air having a desired pressure is ejected from the entire ejection section of the air flow path formed of the gap formed in an annular shape in the frame. It is hoped that However, in the configuration in which the compressed air supplied to the air flow path via the supply flow path is directly ejected from the ejection section, the compressed air ejected from each section (in the circumferential direction) of the ejection section The amount of jetting increases in the vicinity of the communication position of the supply flow path with respect to the air flow path, and decreases as the distance from the communication position increases. Therefore, in the structure, there exists a possibility that the state where the compressed air of a desired pressure may not be ejected may occur in the portion of the ejection portion that is away from the communication position.

  On the other hand, the rotary table device according to the present invention has, as a configuration for the sealing device, an annular storage portion in which the air flow path described above is formed on the bearing side with respect to the ejection portion, and the storage portion is In the air flow path including itself, it has a configuration in which the gap is larger than the gap in the portion on the downstream side of itself. And according to the structure, the compressed air supplied to the air flow path via the supply flow path is temporarily stored in the storage section, and then passes through the downstream portion of the air flow path. It will be ejected from the said ejection part. Moreover, as a result of being temporarily stored in the storage part as described above, the pressure of the compressed air is substantially uniform throughout the annular air flow path in the storage part. Therefore, according to such a sealing device, since the compressed air is ejected from the ejection section with a substantially uniform pressure over the entire ejection section, the pressure of the compressed air supplied through the supply flow path is reduced. By setting to an appropriate one, compressed air having a desired pressure is ejected over the entire ejection portion, and a complete seal state is realized.

It is a front view which shows one Embodiment of the rotary table apparatus by this invention. It is a principal part enlarged view of the front view which shows one Embodiment of the rotary table apparatus by this invention. It is a front view which shows another embodiment of the turntable apparatus by this invention.

  Below, based on FIG. 1, 2, one Example (Example) of this invention is described.

  As shown in FIGS. 1 and 2, the rotary table device 1 includes a frame 10 having a receiving hole 14, and a rotary shaft 20 that is rotatably supported by the frame 10 through a bearing 30 in the receiving hole 14. ing. Further, the rotary table device 1 includes a drive device 50 for rotationally driving the rotary shaft 20 and a clamp device 60 for holding the rotary shaft 20 during indexing. Hereinafter, each configuration of the rotary table device 1 will be described in detail.

  The frame 10 includes a main body portion 11, a cover portion 12, and a base portion 13 each having a through hole having an inner diameter through which the rotary shaft 20 can be inserted. The main body 11 is a portion that occupies most of the frame 10 in the insertion direction of the rotating shaft 20, and is a main portion of the frame 10. Moreover, the main-body part 11 has a through-hole as mentioned above, The through-hole opens in the both end surfaces in the main-body part 11, ie, the end surface of the other end side from the end surface of the one end side in the main-body part 11. It is the structure formed so that it might penetrate toward. Furthermore, the main body 11 has a configuration in which the inner diameter of the through hole is enlarged in a range from the substantially center to the end surface on the other end side in the through direction of the through hole. In other words, in the main body 11, the through hole is formed so as to have a large-diameter portion whose inner diameter is larger than the portion on the one end side in the range.

  The cover portion 12 is a plate-like member, and the through-hole direction of the cover portion 12 is made to coincide with the through-hole direction of the through-hole in the main body portion 11 and the center of the through-hole is the center of the through-hole of the main body portion 11 in plan view It is attached to the main body 11 in such a manner that one end face thereof is opposed to the end face on the one end side of the main body with an arrangement that coincides with the center.

  The base portion 13 is a ring-shaped member having an outer diameter that can be inserted into the large diameter portion of the through hole of the main body portion 11. The base portion 13 is fitted into the large-diameter portion of the through hole of the main body portion 11 on the outer peripheral surface, and the position of one end surface in the through direction of the through hole is the end surface on the other end side of the main body portion 11. It is attached to the main body 11 in an arrangement that matches the position of the main body 11.

  And the frame 10 is comprised by attaching the cover part 12 and the base part 13 with respect to the main-body part 11 as mentioned above. Further, in the frame 10 configured as described above, the through holes of the main body part 11, the cover part 12, and the base part 13 are in a continuous state in the through direction, and the frame 10 is formed by the through holes. The above-mentioned accommodation hole 14 is formed in the inside.

  The rotary shaft 20 is a member to which a disk-like table 40 on which a work is placed is attached (supported) in the rotary table device 1. The rotating shaft 20 is disposed in the housing hole 14 of the frame 10 and is rotatably supported with respect to the frame 10 by a bearing 30 interposed between the rotating shaft 20 and the main body 11. Further, in the state where the rotary shaft 20 is arranged in the accommodation hole 14 as described above, a part of one end side of the rotary shaft 20 is the other end surface (the main body portion 11) of the cover portion 12 of the frame 10. The end surface of the frame 10 is slightly protruded to the outside of the frame 10.

  In addition, the table 40 is attached to the end surface of the one end side portion of the rotary shaft 20 in a direction that matches the plate thickness direction with the axial direction. However, in the mounted state, the table 40 is in a state where the center thereof coincides with the axis of the rotary shaft 20 in plan view. Further, in the mounted state, the rotary table device 1 is in a state in which a space having a narrow interval exists between the end surface of the table 40 on the frame 10 side and the end surface of the frame 10 on the one end side.

  In this embodiment, the drive device 50 is mainly configured by a direct drive motor (DD motor 51) that rotationally drives the rotary shaft 20 without using a drive transmission mechanism such as a gear. Incidentally, the DD motor 51 is a so-called inner rotor type DD motor 51 in which the motor rotor 52 is fixed to the rotary shaft 20 and the motor stator 53 is fixed to the frame 10 so as to surround the motor rotor 52. The driving device 50 includes a stator sleeve 54 interposed between the motor stator 53 and the frame 10. The drive device 50 is disposed concentrically with the axis of the rotary shaft 20 in the large diameter portion of the through hole of the main body 11 of the frame 10. Further, the drive device 50 is connected to a control device of a machine tool (not shown) and the drive is controlled by the control device.

  The driving device 50 is capable of rotationally driving the rotary shaft 20 at a rotational speed such that the peripheral speed is 10 m / s or more. However, the peripheral speed referred to here is the circumference of the one end side portion of the rotating shaft 20 (the portion of the rotating shaft 20 including the portion closest to the table 40 on the outer peripheral surface facing the inner peripheral surface of the accommodation hole 14). Is fast. That is, for the purpose of the present invention, which is to prevent the entry of coolant liquid and dust throwing foreign matter into the inside of the frame 10, it is required to be in a sealed state with the cover portion 12, which is the portion of the frame 10 closest to the table 40. In the present invention, the circumferential speed (rotational speed of the outer peripheral surface) representing the rotational speed of the rotary shaft 20 is a portion of the rotary shaft 20 forming the gap. Is the peripheral speed of the one end side portion.

  With respect to the drive device 50, the stator sleeve 54 is configured in a ring shape, is fitted into the inner peripheral surface of the large diameter portion, and is fixed to the frame 10 by a screw member or the like (not shown). Further, the motor stator 53 is provided in a state in which it cannot rotate relative to the stator sleeve 54 by being fitted (press-fitted) into the inner peripheral surface of the stator sleeve 54. Therefore, the motor stator 53 is provided in a state in which it cannot rotate relative to the frame 10. Furthermore, the motor rotor 52 is provided in a state in which it cannot rotate relative to the rotary shaft 20 by fitting (press-fitting) the rotary shaft 20 into the inner peripheral surface thereof.

  In the present embodiment, the clamp device 60 is a so-called disc-type clamp device that holds the rotary shaft 20 by pressing a piston 62 against a clamp disc 61 attached to the rotary shaft 20. The clamp device 60 is a unclamp type that is always urged toward the direction in which the piston 62 is always separated from the clamp disk 61 (the side opposite to the table 40 side in the axial direction) by the urging force of the spring member. Is.

  With respect to the clamping device 60, the piston 62 is housed in a housing groove formed in the main body 11 of the frame 10, and is provided so as to be displaceable in the axial direction. More specifically, the main body 11 in the frame 10 is an accommodation groove formed so as to open on the end face on the one end side (end face on the cover part 12 side), and the rotation accommodated in the accommodation hole 14 in the frame 10. An annular housing groove is formed concentrically with the axis of the shaft 20. The piston 62 is an annular member formed so as to substantially match the shape of the housing groove in the main body 11. The piston 62 is provided so as to be fitted into the receiving groove, and can be displaced in the axial direction. In the frame 10, there is a clear space communicating with the receiving hole 14 between the cover portion 12 and the inner portion of the end face on the one end side of the main body 11 where the receiving groove opens. doing.

  The clamp disk 61 is a flexible disk-shaped member, is disposed concentrically with the axis of the rotary shaft 20, and is fixed to the rotary shaft 20 by a screw member. However, the clamp disk 61 has an outer diameter larger than the inner diameter of the accommodation hole 14, and is provided so as to be positioned in the gap in the frame 10 due to its arrangement in the axial direction. Further, the clamp disc 61 has an outer diameter such that a portion on the outer peripheral side thereof overlaps with an existing position of the piston 62 when viewed in the axial direction. Therefore, the clamp disk 61 is in a state in which the outer peripheral side portion exists between the piston 62 and the cover portion 12 in the gap in the frame 10.

  In addition, in the clamping device 60, the working fluid (pressure oil or the like) is supplied to the housing groove, so that the piston 62 is displaced toward the cover portion 12 due to the pressure of the working fluid. The clamp disc 61 is sandwiched (clamped) by the cover portion 12. As a result, the clamp disk 61 becomes non-rotatable, and as a result, the rotation shaft becomes non-rotatable. Therefore, in the rotary table device 1, during the indexing process, after the rotary shaft 20 is indexed to the angular position programmed by the drive device 50, the rotary shaft 20 is indexed by operating the clamp device 60. It will be in the state hold | maintained at the taken out angular position, and the process with respect to the workpiece | work on the table 40 will be performed in that state.

  In the rotary table device 1 having the above-described configuration, according to the present invention, the rotary table device 1 ejects compressed air from the inside of the frame 10 to prevent the foreign matter from entering the frame 10. It has. However, the present invention is based on the premise that the rotary table device 1 is used under use conditions in which the rotating shaft is rotationally driven at a high speed such that the peripheral speed is 10 m / s or more. Such an air seal mechanism is provided for the table device 1. The details of the air seal mechanism are as follows.

  The air seal mechanism supplies compressed air to a space inside the frame 10 (more specifically, a space between the inner peripheral surface of the accommodation hole 14 and the outer peripheral surface of the rotary shaft 20 in the frame 10). Compressed air is ejected from the end portion on the table 40 side (in the configuration of the present embodiment, the portion between the inner peripheral surface of the through hole in the cover portion 12 and the outer peripheral surface of the rotary shaft 20), and into the frame 10 This prevents intrusion of the foreign matter. For this purpose, the turntable device 1 includes a supply flow path 70 formed so as to communicate with the space.

  Although the space in the frame 10 exists over the range where the rotary shaft 20 exists in the axial direction, the rotary shaft 20 is supported by the bearing 30 with respect to the frame 10. 30 is substantially divided into a part on the cover part 12 side and a part on the base part 13 side. And since the part 80 by the side of the cover part 12 in the said space contains the part between the inner peripheral surface of the through-hole in the above-mentioned cover part 12, and the outer peripheral surface of the rotating shaft 20, the supply flow path 70 is the It is formed in the main body part 11 of the frame 10 so as to communicate with the part 80 on the cover part 12 side. Accordingly, the portion 80 on the cover 12 side of the bearing 30 in the space corresponds to the air gap (inside the frame) in the present invention.

  In this configuration, the compressed air supplied to the gap 80 passes through the gap 80 and is ejected from a portion between the inner peripheral surface of the through hole of the cover portion 12 and the outer peripheral surface of the rotary shaft 20 in the gap 80. To do. Therefore, the air gap 80 functions as a flow path through which compressed air passes in the air seal mechanism, and corresponds to the air flow path in the present invention. Further, a portion between the inner peripheral surface of the through hole of the cover portion 12 and the outer peripheral surface of the rotary shaft 20 in the air flow path 80 from which the compressed air is ejected is the most downstream side in the air flow path 80 in the present invention. It corresponds to the ejection part 81 (located).

  In addition, since the space defined by the inner peripheral surface of the accommodation hole 14 and the outer peripheral surface of the rotary shaft 20 in the frame 10 functions as the air flow channel 80 for the air flow channel 80 including the ejection portion 81, the air The flow path 80 exists in a circumferential shape in the frame 10 so as to surround the rotary shaft 20. Therefore, the ejection part 81 is opened circumferentially with respect to the space between the table 40 and the frame 10 in the axial direction. Incidentally, with respect to the peripheral speed, in this configuration, the rotational speed of the outer peripheral surface of the portion defining the ejection portion 81 opening in the space in the portion on the one end side of the rotary shaft 20 corresponds to that.

  In the rotary table device including the air seal mechanism configured as described above, in the present invention, the air seal mechanism makes the pressure of the compressed air ejected from the ejection portion 81 uniform in the air flow path 80 described above. A storage part 82 is further provided for the purpose of ensuring that compressed air is uniformly ejected over the entire circumference of the ejection part 81. Details of the reservoir 82 are as follows.

  First, in the rotary table device 1 according to the present embodiment, the rotary shaft 20 has a diameter-expanded portion 21 formed so that the outer diameter of the rotary shaft 20 is increased at the one end side which is the table 40 side. ing. However, the enlarged diameter portion 21 is located with respect to the rotary shaft 20 at a position that is located on the bearing 30 side of the cover portion 12 with respect to the axial direction in a state where the rotary shaft 20 is disposed in the accommodation hole 14. Is formed. In other words, in the state where the rotary shaft 20 is disposed in the accommodation hole 14 as described above, the diameter-expanded portion 21 is in a state of being located within the existence range of the main body portion 11 in the frame 10 with respect to the axial direction.

  As described above, the accommodation hole 14 in the frame 10 (the through hole in the main body portion 11) is for placing (accommodating) the rotating shaft 20 therein. Therefore, the through hole in the main body 11 has an inner diameter larger than the outer diameter of the enlarged diameter portion 21 of the rotating shaft 20 at least in the range where the enlarged diameter portion 21 exists in the axial direction. A part of the gap 80 is defined by the outer peripheral surface of the enlarged diameter portion 21 in the rotating shaft 20 and the inner peripheral surface of the through hole of the main body 11 facing the outer peripheral surface.

  Further, in the rotary table device 1 of the present embodiment, the bearing 30 that supports the rotary shaft 20 is such that the end surface of the inner ring on the table 40 side of the inner ring is connected to the table 40 side in the enlarged diameter portion 21 of the rotary shaft 20. Is fitted to the rotary shaft 20 in its inner ring in a state of abutting against the opposite end face. In addition, the bearing 30 is fitted to the inner peripheral surface of the through hole in the main body portion 11 in the outer ring in such an arrangement in the axial direction.

  Note that the portion of the main body portion 11 (hereinafter also referred to as “bearing support portion”) 11 a to which the bearing 30 (outer ring) is fitted as described above has an inner diameter that is substantially the same as the outer diameter of the enlarged diameter portion 21. It is formed to become. Thereby, the bearing support portion 11a is located on the inner side in the radial direction with respect to the inner peripheral surface of the through hole in the main body portion 11 facing the outer peripheral surface of the enlarged diameter portion 21, and the inner periphery in the through hole in the radial direction. It exists over the range from the surface to the outer peripheral surface of the enlarged diameter portion 21. And the bearing 30 is located in the presence range of the enlarged diameter part 21 regarding a radial direction.

  Moreover, the bearing support part 11a is formed so that the end surface on the table 40 side is located at substantially the same position as the end surface on the table 40 side of the bearing 30 in the axial direction. Therefore, the end surface on the table 40 side of the bearing support portion 11a is located at the same position as the end surface on the opposite side to the table 40 side in the enlarged diameter portion 21 in the axial direction. Accordingly, a part of the gap 80 defined by the outer peripheral surface of the enlarged diameter portion 21 and the inner peripheral surface of the through hole in the main body portion 11 in the radial direction has one end of the range in the axial direction. It is demarcated by the end surface by the side of the table 40 in the bearing support part 11a.

  In addition, the supply flow path 70 is formed so as to open to the end face on the table 40 side of the bearing support portion 11a at the downstream end thereof. Thereby, the supply flow path 70 is communicated with a space 82 (hereinafter referred to as “first partial space”) 82 forming a part of the gap 80 at the downstream end thereof. Accordingly, the first partial space 82 is the most upstream space of the gap 80 in the gap 80 that is a portion on the cover portion 12 side of the bearing 30 in the space in the frame 10 described above. The supply channel 70 is open to the outer peripheral surface of the main body 11 of the frame 10 at the upstream end.

  Incidentally, the inner diameter of the through hole in the cover portion 12 is smaller than the outer diameter of the enlarged diameter portion 21 in the rotary shaft 20. Thereby, the cover part 12 and the enlarged diameter part 21 overlap with respect to the radial direction. In other words, the inner peripheral surface of the through hole in the cover portion 12 is located on the inner side of the outer peripheral surface of the enlarged diameter portion 21 in the radial direction. Therefore, the first partial space 82 defined by the outer peripheral surface of the enlarged diameter portion 21 in the rotary shaft 20 and the inner peripheral surface of the through hole in the main body portion 11 in the radial direction is the bearing support portion 11a in the axial direction. The range is defined by the end surface on the table 40 side and the one end surface of the cover portion 12.

  Further, the cover portion 12 in the frame 10 and the enlarged diameter portion 21 in the rotating shaft 20 overlap as described above in the radial direction, but are spaced apart from each other in the axial direction. . That is, the cover part 12 in the frame 10 and the enlarged diameter part 21 in the rotary shaft 20 are opposed to each other with a gap in the axial direction. Accordingly, between the frame 10 and the rotary shaft 20, a space defined by the one end surface of the cover portion 12 facing in the axial direction and the end surface of the enlarged diameter portion 21 on the table 40 side (hereinafter referred to as “first”). 2) 83, and the second partial space 83 forms a part of the gap 80 described above. In other words, a part of the gap 80 described above is defined by the one end surface of the cover portion 12 facing in the axial direction and the end surface of the enlarged diameter portion 21 on the table 40 side.

  The second partial space 83 is a space that extends in the radial direction over the protruding range of the enlarged diameter portion 21 from the portion (front end portion) on the side of the table 40 relative to the enlarged diameter portion 21 of the rotary shaft 20. It communicates with the first partial space 82 described above. However, the distance in the axial direction between the one end surface of the cover portion 12 that defines the second partial space 83 and the end surface on the table 40 side of the enlarged diameter portion 21 defines the first partial space 82 described above. The distance between the outer peripheral surface of the enlarged diameter portion 21 and the inner peripheral surface of the through hole in the main body portion 11 is smaller than the radial direction.

  Further, the through hole of the cover portion 12 in the frame 10 forms a part of the accommodation hole 14 as described above, and the tip end portion of the rotary shaft 20 is disposed therein. Therefore, the through hole of the cover portion 12 has an inner diameter that is naturally larger than the outer diameter of the tip portion of the rotary shaft 20. In addition, the inner diameter of the through hole of the cover portion 12 is such that a slight gap is formed between the inner peripheral surface of the through hole and the outer peripheral surface of the distal end portion of the rotary shaft 20 facing the inner surface. .

  Accordingly, a space defined by the outer peripheral surface of the tip portion and the inner peripheral surface of the through hole of the cover portion 12 (hereinafter referred to as “third partial space”) around the tip portion of the rotating shaft 20. .) 81 exists, and the third partial space 81 forms a part of the gap 80 described above. Note that the third partial space 81 communicates with the second partial space 83 and also communicates with the space between the table 40 and the frame 10 described above. Accordingly, the third partial space 81 is a space constituting the most downstream portion of the gap 80. That is, the most downstream portion of the gap 80 is defined by the outer peripheral surface of the tip portion of the rotary shaft 20 and the inner peripheral surface of the through hole in the cover portion 12. Incidentally, the distance in the radial direction between the outer peripheral surface of the tip portion of the rotating shaft 20 defining the third partial space 81 and the inner peripheral surface of the through hole in the cover portion 12 is the second partial space 83 described above. Is smaller than the distance in the axial direction between the one end surface of the cover portion 12 that defines the edge and the end surface of the enlarged diameter portion 21 on the table 40 side.

  As described above, the air gap 80 in the frame 10 serving as the air flow path in the above-described air seal mechanism includes the first partial space 82 on the most upstream side and the third portion on the most downstream side defined as described above. A space 81 and a middle space (midstream portion) between the first partial space 82 and the third partial space 81, and the first partial space 82 and the third partial space 81 communicate with each other. 2 partial spaces 83. The third partial space 81 on the most downstream side corresponds to the above-described ejection portion in the air flow path 80 of the air seal mechanism.

  As described above, the air gap 80 that functions as an air flow path in the air seal mechanism includes the first partial space 82, the second partial space 83, and the third portion formed by the internal configuration of the turntable device 1. When the air flow path 80 is considered as an air flow path 80, the air flow path 80 has an upstream partial flow path (upstream partial flow path) formed by the first partial space 82, and a midstream portion. It can be understood that the partial flow path (middle flow partial flow path) is formed by the second partial space 83 and the downstream partial flow path (downstream partial flow path) is formed by the third partial space 81. . The size of each of the partial flow paths 81, 82, 83 is taken as the width of the flow path with respect to the direction of the flow of compressed air in the air flow path 80 (hereinafter referred to as “flow path width”). be able to. Further, the flow path width corresponds to the interval between the frame 10 and the frame 10 or the part of the rotating shaft 20 that defines the partial flow path in the width direction.

  However, with regard to the direction of the compressed air flow mentioned here, the air seal mechanism is provided for the purpose of preventing the entry of the foreign matter into the frame 10 as described above, and is supplied from the supply flow path 70. The compressed air flows from the upstream side, which is the supply flow path 70 side, toward the ejection portion 81 on the downstream side, and is ejected from the ejection portion 81, thereby achieving its intended function. On the other hand, as described above, the air flow path 80 exists circumferentially around the rotary shaft 20, but the supply of compressed air to the air flow path 80 is not performed all around the air flow path 80. This is done in part of the circumference. Therefore, along with the supply of compressed air from the supply flow path 70, in the air flow path 80, not only the flow of compressed air from the upstream side as described above to the ejection portion 81 but also the circumferential direction is directed. There is also a flow.

  However, the flow of compressed air originally required in the air seal mechanism is a flow in the direction from the upstream side (supply flow channel 70 side) to the ejection portion 81, and the flow in the circumferential direction is the air flow channel. It is only the flow for distributing compressed air to the part on the same circumference in 80. Therefore, as for the air flow path 80 for air sealing, the flow direction of the compressed air for determining the size thereof is the flow direction from the upstream side toward the ejection portion 81. Regarding the air flow path 80, the upstream side here refers not only to the part (part on the circumference) where the supply flow path 70 communicates, but is substantially the same as the part where the supply flow path 70 communicates. Refers to the entire part of the circumference.

  In addition, as described above, the flow channel width of each partial flow channel 81, 23, 83 captured as the size of each partial flow channel 81, 82, 83 in the air flow channel 80 is the air flow channel 80. The frame 10 and the frame 10 or the rotating shaft 20 that define the partial flow paths in the direction of the width of the flow path with respect to the flow direction of the compressed air (the direction of the flow from the upstream side toward the ejection portion 81) It is taken as the interval of the part. Therefore, with respect to the channel width of the upstream partial channel 82, the direction of the flow toward the ejection portion 81 in the upstream partial channel 82 is the axial direction, and the direction of the channel width with respect to the direction of the flow Is the radial direction, the flow path width is the distance between the inner peripheral surface of the through hole and the outer peripheral surface of the enlarged diameter portion 21 in the main body portion 11 that defines the first partial space 82 in the radial direction. It corresponds to.

  As for the channel width of the midstream partial channel 83, the direction of the flow toward the ejection portion 81 in the midstream partial channel 83 is the radial direction, and the direction of the channel width with respect to the direction of the flow Is the axial direction, the flow path width is determined between the one end surface of the cover portion 12 that defines the second partial space 83 in the axial direction and the end surface of the enlarged diameter portion 21 on the table 40 side. Corresponds to the interval. Further, with respect to the flow path width of the downstream partial flow path (spouting portion) 81, the direction of the compressed air flowing through the downstream partial flow path 81 is the axial direction, and the width of the flow path with respect to the flow direction is Since the direction is the radial direction, the flow path width corresponds to the distance between the inner peripheral surface of the through hole in the cover portion 12 that defines the ejection portion 81 in the radial direction and the tip end portion of the rotating shaft. .

  In addition, as described above, in the rotary table device 1, the distance between the inner peripheral surface of the through hole and the outer peripheral surface of the enlarged diameter portion 21 in the main body portion 11 that defines the first partial space 82 in the radial direction. Is larger than the distance between the one end surface of the cover portion 12 that defines the second partial space 83 in the axial direction and the end surface of the enlarged diameter portion 21 on the table 40 side. The flow path 82 has a larger flow path width than the middle flow partial flow path 83 located on the downstream side of itself. Therefore, in the air flow path 80, the upstream partial flow path 82 formed as described above corresponds to the storage section in the present invention.

  Incidentally, as described above, the interval between the one end surface of the cover portion 12 that defines the second partial space 83 in the axial direction and the end surface on the table 40 side of the enlarged diameter portion 21 is the ejection portion in the radial direction. 81 is larger than the distance between the outer peripheral surface at the tip of the rotating shaft that defines the third partial space 81 that is 81 and the inner peripheral surface of the through-hole of the cover portion 12. The flow path width of the ejection part (downstream partial flow path) 81 located on the downstream side is also smaller than the flow path width of the storage part (upstream partial flow path) 82.

  In the turntable device 1 of the present embodiment having the above-described configuration, compressed air is supplied from the air supply device (not shown) to the supply flow path 70 at least during workpiece processing, and the compressed air is supplied. The air is supplied to the air flow path 80 via the flow path 70. Accordingly, in the air flow path 80, the storage section 82, which is the upstream partial flow path located on the upstream side (supply flow path 70 side), passes through the middle flow partial flow path 83 to the ejection section 81, which is the downstream partial flow path. Compressed air flows in the direction of flow such as inflow. The compressed air that has flowed into the ejection portion 81 is ejected from the space between the table 40 and the frame 10 via the ejection portion 81. As a result, at least during the processing of the workpiece, compressed air from the inside of the frame 10 is ejected from the space between the table 40 and the frame 10 to the outside. Intrusion of the foreign matter into the frame 10 is prevented.

  More specifically, the flow of compressed air from the storage unit 82 toward the ejection unit 81 will be described in detail. When high-pressure compressed air is supplied from the supply channel 70 to the air channel 80, the storage unit 82 Is in a state in which the air pressure of the portion communicating with the supply flow path 70 in the storage portion 82 increases according to the pressure of the supplied compressed air. Along with this, a circumferential flow of compressed air is generated in the reservoir 82, whereby the air pressure gradually increases over the entire (total circumference) of the reservoir 82. Further, as the air pressure in the reservoir 82 increases, compressed air flows from the reservoir 82 side in the midstream partial flow channel 83 that communicates with the reservoir 82 and communicates with the space outside the frame 10. To do. As a result, the compressed air that has passed through the midstream partial flow path 83 flows through the ejection portion 81 and is ejected toward the space.

  In addition, as described above, the air flow path 80 is a midstream partial flow path 83 in which the storage portion 82, which is an upstream partial flow path positioned on the upstream side (supply flow path 70 side), communicates with the storage portion 82. In contrast, the flow path width in the flow direction of the compressed air is formed to be large. In other words, the air flow path 80 has a configuration in which the flow path width is narrowed in a portion corresponding to the midstream partial flow path 83. With this configuration, a part of the compressed air supplied from the supply flow path 70 is gradually stored in the storage unit 82. Therefore, in the storage unit 82, the air pressure is increased over the whole (the entire circumference). It becomes a substantially uniform state at a desired level.

  More specifically, in the air flow path 80, with the supply of compressed air from the supply flow path 70, the flow of compressed air from the storage section 82 toward the midstream partial flow path 83 (on the ejection section 81 side) as described above. Will occur. However, as described above, the air flow path 80 has a configuration in which the flow path width in the midstream partial flow path 83 is narrowed with respect to the flow path width of the storage portion 82, and the storage having a large flow path width. Compared to the flow in the circumferential direction in the portion 82, the resistance to the flow of compressed air when flowing from the storage portion 82 into the midstream partial flow path 83 is large.

  Therefore, in the air flow path 80, the compressed air supplied to the storage part 82 flows in a state in which the flow in the circumferential direction is predominant rather than the flow toward the ejection part 81 side. That is, a part of the compressed air supplied to the storage part 82 flows toward the ejection part 81 side, but mainly flows in the storage part 82 and is stored in the storage part 82. Thereby, as the supply of the compressed air from the supply flow path 70 is continued, the compressed air is gradually stored in the reservoir 82, and the pressure of the compressed air supplied over the entire reservoir 82 Air pressure rises to the same extent. As a result, the air pressure in the reservoir 82 is substantially uniform at a pressure corresponding to the pressure of the supplied compressed air over the entire reservoir 82.

  And since the air pressure is in a substantially uniform state over the entire storage section 82, the compressed air flowing from the storage section 82 toward the ejection section 81 is also sent to the entire middle flow partial flow path 83 and the entire ejection section 81. Over the entire circumference, a substantially uniform state is obtained at a pressure corresponding to the pressure of the supplied compressed air. Therefore, by setting the pressure of the compressed air supplied from the supply channel 70 to the air channel 80 to an appropriate value, the compressed air having a desired pressure is directed toward the space over the entire circumference around the rotation shaft 20. Will be ejected. Thereby, the sealing state by the above-described air seal mechanism becomes more complete, that is, the sealing effect by the air seal mechanism is further enhanced.

  Although one embodiment (example) of the rotary table device according to the present invention has been described above, the present invention is not limited to that described in the above embodiment, and another embodiment (deformation) as described below. Example) is also possible.

  Regarding the air flow path in the air seal mechanism, the air flow path 80 in the above-described embodiment includes a storage section in addition to the storage section 82 that is the upstream partial flow path on the most upstream side and the ejection section 81 that is the downstream partial flow path on the most downstream side. 82 and the ejection part 81 are formed, and it has the structure including the midstream partial flow path 83 which connects both. More specifically, in the embodiment, the rotary table device 1 includes the clamp device 60 provided on the side of the table 40 relative to the bearing 30, and the rotary shaft 20 has a diameter-enlarged portion for attaching the clamp disk 61 of the clamp device 60. As a result, the air flow path 80 also includes the midstream partial flow path 83 as described above.

  However, the present invention is not limited to the rotary table device in which the clamp device is arranged as in the above-described embodiment. For example, the clamp device 160 is arranged on the opposite side of the table 140 from the bearing 130 as shown in FIG. The present invention is also applicable to the rotary table device 100 that has been made. Therefore, in the rotary table device 1 of the embodiment, considering the case where the clamping device is arranged in that way, in the configuration, the enlarged diameter portion 21 of the rotary shaft 20 positioned in the gap 80 in the embodiment is used. It can be omitted. When the rotary shaft 20 is not provided with the enlarged diameter portion 21 in the configuration of the embodiment, the air flow path has a configuration in which the midstream partial flow path 83 in the embodiment is omitted, that is, storage. It becomes the structure which a jet part communicates directly with the downstream of a part.

  Thus, the air flow path in the air seal mechanism of the present invention only needs to have at least the ejection part and the storage part, in other words, may be formed only by the ejection part and the storage part. Furthermore, the air flow path is not limited to the configuration in which the storage part is located on the most upstream side of the air flow path as in the above-described embodiment, and the air flow path is configured to have a flow path on the upstream side of the storage part. Also good.

  In addition, regarding the supply flow path, the air seal mechanism in the above-described embodiment is configured such that the supply flow path 70 communicates with the air flow path 80 only at one location. However, in the present invention, the air seal mechanism is not limited to the configuration in which the supply flow path is formed as such, but may have a configuration in which the supply flow path is formed so as to communicate with the air flow path at a plurality of locations. good.

  As such a configuration, for example, a single supply flow path formed in the frame as in the above-described embodiment is branched into two or more at a portion upstream of the communication position with respect to the air flow path, and after the branching It is conceivable that each of the branch flow paths communicates with the air flow path. In the present invention, the number of supply channels in the air seal mechanism is not particularly limited, and the air seal mechanism may include a plurality of independent supply channels. Specifically, the air seal mechanism may have a configuration in which two or more supply flow paths shown in the above-described embodiment and the example of FIG. 3 are formed at different positions in the circumferential direction. Even in this case, the air seal mechanism has a configuration in which the supply flow path is communicated with the air flow path at a plurality of locations. In addition, in the case of the structure, each supply flow path may be configured to be connected to a single air supply apparatus, or another air supply apparatus provided corresponding to each supply flow path. The structure connected to may be sufficient.

  In the embodiment described above, the drive device in the rotary table device according to the present invention is the drive device 50 mainly composed of the DD motor 51 that directly rotates the rotary shaft 20. Yes. However, the drive device in the rotary table device on which the present invention is based is not limited to such a configuration, and may be one using a worm gear mechanism as shown in FIG. Incidentally, the driving device 150 in the rotary table device 100 shown in FIG. 3 is supported so as to be rotatable with respect to the frame 110 in such a manner as to be engaged with the worm wheel 151 and the worm wheel 151 that are mounted so as not to rotate relative to the rotary shaft 120. The drive transmission mechanism includes a worm spindle 152 and a drive motor (not shown) that rotationally drives the worm spindle 152.

  As for the clamping device, in the above-described embodiment, a so-called disk-type clamping device 60 that holds the rotating shaft 20 in a non-rotatable state by pressing the piston 62 against the clamp disk 61 fixed to the rotating shaft 20 is provided. It has been adopted. However, the clamping device in the rotary table device premised on the present invention is not limited to such a disk type, and may be other known clamping devices. Incidentally, as another known clamping device, the rotating shaft is held by the frictional force generated on the contact surface by bending the clamping sleeve provided around the rotating shaft in the reduced diameter direction and bringing it into contact with the rotating shaft. A so-called sleeve-type clamping device or a tooth formed on the opposing surfaces of both coupling members by moving one of the coupling members provided facing each other in the frame and the rotating shaft toward the other by the pressure of the working fluid, etc. There is a so-called coupling type clamping device that holds the rotating shaft by meshing.

  Furthermore, the present invention is not limited to any of the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Rotary table apparatus 10 Frame 11 Main part 11a Bearing support part 12 Cover part 13 Base part 14 Housing hole 20 Rotating shaft 30 Bearing 40 Table 50 Drive apparatus 51 DD motor 52 Motor rotor 53 Motor stator 54 Stator sleeve 60 Clamp apparatus 61 Clamp disk 62 Piston 70 Supply flow path 80 Air flow path 81 Spout part (downstream partial flow path)
82 Reservoir (upstream partial flow path)
83 Middle stream partial flow path 100 Rotary table device 110 Frame 120 Rotating shaft 130 Bearing 140 Table 150 Drive device 151 Worm wheel 152 Warm spindle 160 Clamp device 170 Supply flow channel 180 Air flow channel

Claims (1)

A rotating shaft having a disk-like table to which a workpiece is attached fixed at one end, a frame having a receiving hole for receiving the rotating shaft and rotatably supporting the rotating shaft by a bearing in the receiving hole; A driving device that rotationally drives the rotating shaft; and a clamping device that holds the rotating shaft at the indexed angular position during indexing. The driving device causes the rotating shaft to rotate at a peripheral speed of 10 m / s. In the rotary table device for machine tools that is rotationally driven as described above,
Formed in the frame so as to communicate with a space inside the frame defined by an inner peripheral surface of the housing hole and an outer peripheral surface of the rotating shaft in the frame, which is located closer to the table than the bearing. An air seal mechanism including a supply flow path, wherein the gap functions as an air flow path when compressed air is supplied through the supply flow path and the compressed air is supplied to the air flow path. An air seal mechanism that prevents intrusion of foreign matter into the frame by ejecting compressed air from the inside of the frame;
The air flow path has a storage part on the upstream side of the ejection part which is the most downstream part in the air flow path,
The rotary table device, wherein the storage section has a flow path width larger than a flow path width of a portion of the air flow path on the downstream side of the storage section.

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